/*
 * Copyright (c) 2011 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** Attributations
 *
 * tetris.h 8.1 (Berkeley) 5/31/93
 * NetBSD: tetris.h,v 1.2 1995/04/22 07:42:48 cgd
 * OpenBSD: tetris.h,v 1.9 2003/06/03 03:01:41 millert
 *
 * Based upon BSD Tetris
 *
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.
 *      Distributed under BSD license.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek and Darren F. Provine.
 *
 */

/** @addtogroup tetris
 * @{
 */
/** @file
 */

#include <stdint.h>

/*
 * Definitions for Tetris.
 */

/*
 * The display (`board') is composed of 23 rows of 12 columns of characters
 * (numbered 0..22 and 0..11), stored in a single array for convenience.
 * Columns 1 to 10 of rows 1 to 20 are the actual playing area, where
 * shapes appear.  Columns 0 and 11 are always occupied, as are all
 * columns of rows 21 and 22.  Rows 0 and 22 exist as boundary areas
 * so that regions `outside' the visible area can be examined without
 * worrying about addressing problems.
 */

/* The board */
#define B_COLS  12
#define B_ROWS  23
#define B_SIZE  (B_ROWS * B_COLS)

typedef uint32_t cell;

extern cell board[B_SIZE];  /* 1 => occupied, 0 => empty */

/* The displayed area (rows) */
#define D_FIRST  1
#define D_LAST   22

/* The active area (rows) */
#define A_FIRST  1
#define A_LAST   21

/*
 * Minimum display size.
 */
#define MINROWS  23
#define MINCOLS  40

/* Current screen size */
extern int Rows;
extern int Cols;

/*
 * Translations from board coordinates to display coordinates.
 * As with board coordinates, display coordiates are zero origin.
 */
#define RTOD(x)  ((x) - 1)
#define CTOD(x)  ((x) * 2 + (((Cols - 2 * B_COLS) >> 1) - 1))

/*
 * A `shape' is the fundamental thing that makes up the game.  There
 * are 7 basic shapes, each consisting of four `blots':
 *
 *      X.X       X.X           X.X
 *        X.X   X.X     X.X.X   X.X     X.X.X   X.X.X   X.X.X.X
 *                        X             X           X
 *
 *          0     1       2       3       4       5       6
 *
 * Except for 3 and 6, the center of each shape is one of the blots.
 * This blot is designated (0, 0).  The other three blots can then be
 * described as offsets from the center.  Shape 3 is the same under
 * rotation, so its center is effectively irrelevant; it has been chosen
 * so that it `sticks out' upward and leftward.  Except for shape 6,
 * all the blots are contained in a box going from (-1, -1) to (+1, +1);
 * shape 6's center `wobbles' as it rotates, so that while it `sticks out'
 * rightward, its rotation---a vertical line---`sticks out' downward.
 * The containment box has to include the offset (2, 0), making the overall
 * containment box range from offset (-1, -1) to (+2, +1).  (This is why
 * there is only one row above, but two rows below, the display area.)
 *
 * The game works by choosing one of these shapes at random and putting
 * its center at the middle of the first display row (row 1, column 5).
 * The shape is moved steadily downward until it collides with something:
 * either  another shape, or the bottom of the board.  When the shape can
 * no longer be moved downwards, it is merged into the current board.
 * At this time, any completely filled rows are elided, and blots above
 * these rows move down to make more room.  A new random shape is again
 * introduced at the top of the board, and the whole process repeats.
 * The game ends when the new shape will not fit at (1, 5).
 *
 * While the shapes are falling, the user can rotate them counterclockwise
 * 90 degrees (in addition to moving them left or right), provided that the
 * rotation puts the blots in empty spaces.  The table of shapes is set up
 * so that each shape contains the index of the new shape obtained by
 * rotating the current shape.  Due to symmetry, each shape has exactly
 * 1, 2, or 4 rotations total; the first 7 entries in the table represent
 * the primary shapes, and the remaining 12 represent their various
 * rotated forms.
 */
struct shape {
	int rot;     /* index of rotated version of this shape */
	int rotc;    /* -- " -- in classic version  */
	int off[3];  /* offsets to other blots if center is at (0,0) */
	uint32_t color;
};

extern const struct shape shapes[];

extern const struct shape *curshape;
extern const struct shape *nextshape;

/*
 * Shapes fall at a rate faster than once per second.
 *
 * The initial rate is determined by dividing 1 million microseconds
 * by the game `level'.  (This is at most 1 million, or one second.)
 * Each time the fall-rate is used, it is decreased a little bit,
 * depending on its current value, via the `faster' macro below.
 * The value eventually reaches a limit, and things stop going faster,
 * but by then the game is utterly impossible.
 */
extern long fallrate;  /* less than 1 million; smaller => faster */

#define faster()  (fallrate -= fallrate / 3000)

/*
 * Game level must be between 1 and 9.  This controls the initial fall rate
 * and affects scoring.
 */
#define MINLEVEL  1
#define MAXLEVEL  9

/*
 * Scoring is as follows:
 *
 * When the shape comes to rest, and is integrated into the board,
 * we score one point.  If the shape is high up (at a low-numbered row),
 * and the user hits the space bar, the shape plummets all the way down,
 * and we score a point for each row it falls (plus one more as soon as
 * we find that it is at rest and integrate it---until then, it can
 * still be moved or rotated).
 *
 * If previewing has been turned on, the score is multiplied by PRE_PENALTY.
 */
#define PRE_PENALTY  0.75

extern int score;  /* The obvious thing */

extern char key_msg[116];
extern int showpreview;
extern int classic;

extern int fits_in(const struct shape *, int);
extern void place(const struct shape *, int, int);
extern void stop(const char *);

/** @}
 */
